Resistive random-access memory draws more and more attention. Resistive random-access memory has advantages of such as high density, low cost, low power consumption, high operation speed, good data storage and simple structure.
Basic structure of a resistive random-access memory is classified as 1T1R (one transistor and one resistor) and 1T1D (one transistor and one diode). By applying bias voltage to change resistance of the resistive random-access memory to perform programming or erase, the resistive random-access memory is in a high resistance state or a low resistance state, that is, in logic o or logic 1.
Common types of the resistive random-access memory includes: a Transition Metal Oxide (TMO) ReRAM, a conduction bridge memory and a phase change memory.
For better control, usually, a memory element is coupled to a transistor (i.e. 1T1R). In order to program the memory element, a current flows through the memory element in one direction; and in order to erase the memory element, another current flows through the memory element in a reverse direction. One of the efforts is to improve operation efficiency of the resistive random-access memory and to lower operation failure rate.